Screw-cutting machine



J. A. BECHER.

SCREW CUTTING MACHINE.

APPLICATION FILED JUNE 24, I919.

1,420,01 3. v PatentedJuhe 20, 192 2.

2 SHEETS-SHEET 1.

[N VE/V TOR JAMES A. BECKER, OF CHICAGQ, ILLINOIS.

SCREW-CUTTING- MACHINE.

Application filed June 24,

To all whom it may concern Be it known that I, JAMns A. BECKER, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Screw-Cutting Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in screw cutting machines and particularly to the cutter-head,one object of the invention being to cheapen the construction of the cutter-head without detracting from its eficiency by reducing the amount of milling and drilling necessary in its manufacture.

A further object is to so pivotally support the jaws of the cutter-head that said jaws will recede properly from their work when the cutter-head opens and be prevented from so plunging forwardly as to strike the head of the bolt when the threads are cut closely up to the head of the bolt.

\Vith these and other objects in View, the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in elevation showing the jaws of the cutter-head closed. Fig. 9. is a similar view showing the jaws open. Fig. 3 is a plan or face view. Fig. 4 is a sectional view on the line 4t 1 of Figure 1. Fig. 5 is a sectional view on the line of Figure 2, and Figs. 6, 7 and 8 are detail views.

1 represents the shaft by which my improved cutter-head is carried,--said shaft being provided at or near its end with diametrically opposite trunnions 22 which constitute pivot mountings for the jaws of the cutter-head as hereinafter explained. Each jaw 3 is provided in its outer face with grooves or recesses in which cutters 4- are mounted. These cutters may be held in place by means of headed screws 5, as shown in Figure 3, and the cutters may be adjusted relatively to the work, by means of screws 6. I

Each jaw 3 is provided with two arms 7-7 and each of these arms is made with a recessed portion 8 and a curved flange 9 in line with said recessed portion. The recessed portions .8 and the adjacent curved Specification of Letters Patent. Patented June 2t), 1922,

1918. Serial No. 306,351.

flanges 9 of one jaw constitute half-bearings for said jaw on the respective tr'unnions 2 2. The other jaw, being similarly constructed, is also mounted on said trunnions. The respective half-bearings of the respectiye jaws are held in place on the trunnions at diametrically opposite sides of the shaft 1, by means of collars 10 and these collars are held in place by disks 11, as shown in Figures a and 5. The disks 11 are secured in position by means of screws 12, the threaded portions of which enter the trunnions 2 and the heads of said screws being caused to engage the outer faces of the disks. From this construction it will be seen that the axis of the pivotal mounting of the jaws is at right angles to the axis of the cutter-head and shaft 1. By thus mounting the jaws they will recede properly from the work.

Springs 13 serve to move the jaws 3 apart and for the purpose of moving said jaws toward each other to cause the cutters to engage the work, the devices now to be explained are employed: Each jaw is pro vided with a finger let and a grooved collar 15 mounted to rotate with and to slide on the shaft 1, is constructed to co-operate with said fingers to close the jaws and said collar is provided with a portion 16 against which the fingers 14 of the jaws rest when said jaws are open, as shown in Figure 2.

Various slight changes might be made in the details of construction of my invention without departing from the spirit thereof or limiting its scope and hence I do not wish to restrict m self to the precise details herein set forth.

Having fully described my invention what I claim as new and desire to secure by Letters-Patent, is:

1. In a screw cutting machine, the combination with a shaft provided near one end with diametrically opposite trunnions, of two jaws, each provided with part-bean ings mounted on and supported by the two trunnions, means engaging said part-bearings to hold the aws in place on the trunnions, and cutters carried by said jaws.

2. In a screw cutting machine, the combination with a member provided with diametrically opposite trunnions, of two jaws, each having two arms, each having partial bearing members mounted on and supported. by said trunnions, means engaging said partial bearing members for holding said tering the trunnions, and cutters carried by 10 said jaws.

In testimony whereof, I have signed this specification in the presence of two snbscrilr 111 witnesses.

JAMES A. BECHER. VVit'nesses:

LEWIS BLONTROGK, CHAS. GNOTOVICH. 

